Of the many characteristics of Homo sapiens proposed to distinguish the species--symboling, tool-inventing, language-using--let us propose another: human beings feel a need to explain. Certainly the need applies to Peter Farb who sets out to account for the major features of humankind, from inception to the present. The result is a monumental tome of popular anthropology, sociology, psychology, cultural history, forecast. Clearly he's done a lot of homework. Much was already amassed in such earlier Farb works as Man's Rise to Civilization. This new tome reveals the same faculty for synthesis, for clear good writing, for touching the right scholarly bases. But there is a but. Farb has tried to do too much: to explain and sometimes explain away an array of traits, vast but arbitrary--marriage customs and incest taboos, male dominance, aging, Santa Claus, the psychology of learning, memory. . . . Often the technique is to examine assorted theories, discarding them one by one until at chapter end there emerges the Farbian choice. It may be the belief that women need man's physical strength to protect them and so have submitted to dominance, or that incest taboos are the result of hominid necessity and exogamy, or that peasants at all times have been suspicious, conservative, improvident as a result of their eternal exploitation by power-wielders. Readers will criticize and carp. Some may like the intellectual battling. The problem with books of this kind is that the traits discussed, the very words used, reveal a cultural boundedness. In the end Farb's version of H. sapiens is that of a liberal 20th-century Western intellectual with a sense of history and a belief in the fundamental capacity of ""modernization"": technology and planning will extricate the species from its present predicaments. The optimistic epilogue may surprise the reader, for the earlier sections present not too sanguine a picture; indeed, there is a kind of yearning for the hunting-gathering society. Farb has given us not a definitive pulsebeat of humanity, but a potpourri of interesting facts and artful speculations, at times heady and subtle, at times simplistic and flat.